Electromechanical gyroscopes are used to determine direction of a moving platform based upon the sensed inertial reaction of an internally moving proof mass. An electromechanical gyroscope may include a suspended proof mass, gyroscope case, pickoffs, torquers and readout electronics. The inertial proof mass is internally suspended from the gyroscope case that is rigidly mounted to a platform (such as a vehicle). The gyroscope case communicates inertial motion of the platform to the proof mass while otherwise isolating the proof mass from external disturbances. The pickoffs sense the internal motion of the proof mass and the torquers maintain or adjust the internal motion. The readout electronics may be in close proximity to the proof mass. For example, the readout electronics may be internally mounted to the case. The case provides electrical connections to platform electronics and to a power supply. The case may also provide a mechanical interface to attach and align the gyroscope with the vehicle platform. In various forms gyroscopes may be employed as a sensor for vehicles such as aircraft and spacecraft. They are generally useful for navigation and to autonomously determine the orientation of a free object.
Older mechanical gyroscopes tended to be relatively heavy mechanisms that employed relatively large spinning masses. More recently, some planar resonator gyroscope devices have been developed (such as, disc resonator gyroscopes). Planar resonator gyroscopes may operate through excitation and sensing of in-plane vibrational modes of a substantially solid planar resonator. For example, a planar resonator may be formed of a material such as silicon or quartz.